Mental disorder or mental illness are terms used to refer a psychological or physiological pattern that occurs in an individual and is usually associated with distress or disability that is not expected as part of normal development or culture. The recognition and understanding of mental disorders has changed over time. Definitions, assessments, and classifications of mental disorders can vary, but guideline criterion listed in the ICD, DSM and other manuals are widely accepted by mental health professionals. Categories of diagnoses in these schemes may include mood disorders, anxiety disorders, psychotic disorders, eating disorders, developmental disorders, personality disorders, and many other categories. In many cases there is no single accepted or consistent cause of mental disorders, although they are widely understood in terms of a diathesis-stress model and biopsychosocial model. Mental disorders have been found to be common, with over a third of people in most countries reporting sufficient criteria at some point in their life. Mental health services may be based in hospitals or in the community. Mental health professionals diagnose individuals using different methodologies, often relying on case history and interview. Psychotherapy and psychiatric medication are two major treatment options, as well as supportive interventions. Treatment may be involuntary where legislation allows. A number of movements campaign for changes to mental health services and attitudes, including the Consumer/Survivor Movement. There are widespread problems with stigma and discrimination.

Psychiatric theories and treatments for mental illness developed in Islamic medicine in the Middle East, notably from the 8th century at the Baghdad Hospital under the physician Al-Razi or Rhazes.

Medieval Europe had focused on demonic possession as the explanation of aberrant behavior.[3]Paracelsus used the word lunatic to describe behavior thought to be caused by the lunar effect.[4] Many other terms for mental disorder that found their way into everyday use have been traced to initial use in the 16th and 17th centuries. [5] Shakespeare and his contemporaries frequently depicted mental disorders in their plays. [6] Conditions of "shell shock" came to be recognized in war veterans. Homosexuality was viewed as a mental illness. From the early study of mental illness through individuals such as Philippe Pinel, Sigmund Freud, and Alois Alzheimer, much has changed in the development and understanding of mental illness and continues to change today.

Classification

The definition and classification of mental disorder is a key issue for the mental health professions and for users and providers of mental health services. Most international clinical documents use the term "mental disorder" rather than "mental illness". There is no single definition and the inclusion criteria are said to vary depending on the social, legal and political context. In general, however, a mental disorder has been characterized as a clinically significant behavioral or psychological pattern that occurs in an individual and is usually associated with distress, disability or increased risk of suffering. There is often a criterion that a condition should not be expected to occur as part of a person's usual culture or religion. The term "serious mental illness" (SMI) is sometimes used to refer to more severe and long-lasting disorder. A broad definition can cover mental disorder, mental retardation, personality disorder and substance dependence. The phrase "mental health problems" may be used to refer only to milder or more transient issues.

Some approaches to classification do not employ distinct categories based on cut-offs separating the abnormal from the normal. They are variously referred to as spectrum, continuum or dimensional systems. There is a significant scientific debate about the relative merits of a categorical or a non-categorical system. There is also significant controversy about the role of science and values in classification schemes, and about the professional, legal and social uses to which they are put.

Patterns of belief, language use and perception can become disordered. Psychotic disorders centrally involving this domain include Schizophrenia and Delusional disorder. Schizoaffective disorder is a category used for individuals showing aspects of both schizophrenia and affective disorders. Schizotypy is a category used for individuals showing some of the traits associated with schizophrenia but without meeting cut-off criteria.

There may be an emerging consensus that personality disorders, like personality traits in the normal range, incorporate a mixture of more acute dysfunctional behaviors that resolve in relatively short periods, and maladaptive temperamental traits that are relatively more stable.[12] Non-categorical schemes may rate individuals via a profile across different dimensions of personality that are not seen as cut off from normal personality variation, commonly through schemes based on the Big Five personality traits.[13]

Other disorders may involve other attributes of human functioning. Eating practices can be disordered, at least in relatively rich industrialized areas, with either compulsive over-eating or under-eating or binging. Categories of disorder in this area include Anorexia nervosa and Bulimia nervosa or Binge eating disorder. Sleep disorders such as Insomnia also exist and can disrupt normal sleep patterns. Sexual and gender identity disorders, such as Dyspareunia or Gender identity disorder or ego-dystonic homosexuality. People who are abnormally unable to resist urges, or impulses, to perform acts that could be harmful to themselves or others, may be classed as having an impulse control disorder, including various kinds of Tic disorders such as Tourette's Syndrome, and disorders such as Kleptomania (stealing) or Pyromania (fire-setting). Substance-use disorders include Substance abuse disorder. Addictive gambling may be classed as a disorder. Inability to sufficiently adjust to life circumstances may be classed as an Adjustment disorder. The category of adjustment disorder is usually reserved for problems beginning within three months of the event or situation and ending within six months after the stressor stops or is eliminated. People who suffer severe disturbances of their self-identity, memory and general awareness of themselves and their surroundings may be classed as having a Dissociative identity disorder, such as Depersonalization disorder or Dissociative Identify Disorder itself (which has also been called multiple personality disorder, or "split personality".). Factitious disorders, such as Munchausen syndrome, also exist where symptoms are experienced and/or reported for personal gain.

Disorders appearing to originate in the body, but thought to be mental, are known as somatoform disorders, including Somatization disorder. There are also disorders of the perception of the body, including Body dysmorphic disorder. Neurasthenia is a category involving somatic complaints as well as fatigue and low spirits/depression, which is officially recognized by the ICD-10 but not by the DSM-IV.[14] Memory or cognitive disorders, such as amnesia or Alzheimer's disease exist.

Causes

Numerous factors have been linked to the development of mental disorders. In many cases there is no single accepted or consistent cause. A common view is that disorders often result from genetic vulnerabilities combining with environmental stressors (Diathesis-stress model). An eclectic or pluralistic mix of models may be used to explain particular disorders. The primary paradigm of contemporary mainstream Western psychiatry is said to be the biopsychosocial (BPS) model - incorporating biological, psychological and social factors - although this may not be applied in practice. Biopsychiatry has tended to follow a biomedical model, focusing on "organic" or "hardware" pathology of the brain. Psychoanalytic theories have been popular but are now less so. Evolutionary psychology may be used as an overall explanatory theory. Attachment theory is another kind of evolutionary-psychological approach sometimes applied in the context for mental disorders. A distinction is sometimes made between a "medical model" or a "social model" of disorder and related disability.

Genetic studies have indicated that genes often play an important role in the development of mental disorders, via developmental pathways interacting with environmental factors. The reliable identification of connections between specific genes and specific categories of disorder has proven more difficult.

Environmental events surrounding pregnancy and birth have also been implicated. Traumatic brain injury may increase the risk of developing certain mental disorders. There have been some tentative inconsistent links found to certain viral infections, to substance misuse, and to general physical health.

Social influences have been found to be important, including abuse, bullying and other negative or stressful life experiences. The specific risks and pathways to particular disorders are less clear, however. Aspects of the wider community have also been implicated, including employment problems, socioeconomic inequality, lack of social cohesion, problems linked to migration, and features of particular societies and cultures.

Diagnosis

Many mental health professionals, particularly psychiatrists, seek to diagnose individuals by ascertaining their particular mental disorder. Some professionals, for example some clinical psychologists, may avoid diagnosis in favor of other assessment methods such as formulation of a client's difficulties and circumstances.[15] The majority of mental health problems are actually assessed and treated by family physicians during consultations, who may refer on for more specialist diagnosis in acute or chronic cases. Routine diagnostic practice in mental health services typically involves an interview (which may be referred to as a mental status examination), where judgements are made of the interviewee's appearance and behavior, self-reported symptoms, mental health history, and current life circumstances. The views of relatives or other third parties may be taken into account. A physical examination to check for ill health or the effects of medications or other drugs may be conducted. Psychological testing is sometimes used via paper-and-pen or computerized questionnaires, which may include algorithms based on ticking off standardized diagnostic criteria, and in relatively rare specialist cases neuroimaging tests may be requested, but these methods are more commonly found in research studies than routine clinical practice.[16][17] Time and budgetary constraints often limit practicing psychiatrists from conducting more thorough diagnostic evaluations.[18] It has been found that most clinicians evaluate patients using an unstructured, open-ended approach, with limited training in evidence-based assessment methods, and that inaccurate diagnosis may be common in routine practice.[19]

Comorbidity is very usual with mental disorders, i.e. same person can suffer one or more disorder. The work for fifth version of Diagnostic and Statistical Manual of Mental Disorders (DSM-V)
[20] has raised some questions about dimensional diagnostic criteria compared to categorical diagnostic criteria. Journal of Abnormal Psychology (Vol 114, Issue 4) [21] devoted a whole issue to discuss about categorical and dimensional diagnostic criteria. In short it the argument is that diagnosis of mental disorder can be based on several overlapping dimensions and not categorical and/or two-dimensional classes. One possibility in diagnosis is to have several (>2) dimensions overlapping and that it is harder to describe. In the following picture idea is that multiple dimension lines are crossed with one diagnostic line and the combination of crossing points is basis for a diagnosis.
File:Multidimensional diagnosis.JPG

In practical clinical settings it might be problematic to find several disorders in different dimensions and also differentiate the position of specific disorder in its dimensional axis like the picture indicates.

Treatment

Mental health services may be based in hospitals, clinics or the community. Often an individual may engage in different treatment modalities. They may be under case management (sometimes referred to as "service coordination"), use inpatient or day treatment, utilize a psychosocial rehabilitation program, and/or take part in an Assertive Community Treatment program. Individuals may be treated against their will in some cases, especially if assessed to be at high risk to themselves or others. Services in some countries are increasingly based on a Recovery model that supports an individual's journey to regain a meaningful life.

Prognosis

There is substantial variation over time between disorders, and between individuals. Functional ability may also vary across different domains. There may be remission of symptoms, but also relapse. Rates of recovery vary. A number of individual and social factors have been linked to prognosis.

Despite often being characterized in purely negative terms, mental disorders can involve above-average creativity, non-conformity, goal-striving, meticulousness, or empathy.[22] The public perception of the level of disability associated with mental disorders can change.[23]

Prevalence

WHO estimated that about 450 million people worldwide currently suffer from some form of mental or behavioural disorder.[24] One in four people will suffer from mental illness at some time in life, according to a report from the WHO.[25][26]

Professions and fields

A number of professions have developed that specialise in the treatment of mental disorders, including the medical speciality of psychiatry (including psychiatric nursing)[27][28][29], the division of psychology known as clinical psychology[30], Social Work[31], as well as Mental Health Counselors, Marriage and Family Therapists, Psychotherapists, Counselors and Public Health professionals. Those with personal experience of using mental health services are also increasingly involved in researching and delivering mental health services and working as mental health professionals.[32][33][34][35] The different clinical and scientific perspectives draw on diverse fields of research and theory, and different disciplines may favor differing models, explanations and goals.[22]

Movements

The Consumer/Survivor Movement (also known as user/survivor movement) is made up of individuals (and organizations representing them) who are clients of mental health services or who consider themselves "survivors" of mental health services. The movement campaigns for improved mental health services and for more involvement and empowerment within mental health services, policies and wider society.[36][37][38]Patient advocacy organizations have expanded with increasing deinstitutionalization in developed countries, working to challenge the stereotypes, stigma and exclusion associated with psychiatric conditions. An antipsychiatry movement fundamentally challenges mainstream psychiatric theory and practice, including the reality or utility of psychiatric diagnoses of mental illnesses.[39][40][41]

Laws and policies

Three quarters of countries around the world have mental
health legislation. Compulsory admission to mental health facilities (also known as Involuntary commitment or sectioning), is a controversial topic. From some points of view it can impinge on personal liberty and the right to choose, and carry the risk of abuse for political, social and other reasons; from other points of view, it can potentially prevent harm to self and others, and assist some people in attaining their right to healthcare when unable to decide in their own interests.[42]

All human-rights orientated mental health laws require proof of the presence of a mental disorder as defined by internationally accepted standards, but the type and severity of disorder that counts can vary in different jurisdictions. The two most often utilized grounds for involuntary admission are said to be serious likelihood of immediate or imminent danger to self or others, and the need for treatment. Applications for someone to be involuntarily admitted may usually come from a mental health practitioner, a family member, a close relative, or a guardian. Human-rights-orientated laws usually stipulate that independent medical practitioners or other accredited mental health practitioners must examine the patient separately and that there should be regular, time-bound review by an independent review body.[42] An individual must be shown to lack the capacity to give or withhold informed consent (i.e. to understand treatment information and its implications). Proxy consent (also known as substituted decision-making) may be given to a personal representative, a family member or a legally appointed guardian, or patients may have been able to enact an advance directive as to how they wish to be treated.[42] The right to supported decision-making may also be included in legislation.[43] Involuntary treatment laws may be extended to those living in the community, for example Community Treatment Orders (CTOs) are used in New Zealand, Australia and 38 states in the US and are being planned in the UK.[44]

Perception and discrimination

Media

Media coverage of mental illness comprises predominantly negative depictions, for example, of incompetence, violence or criminality, with far less coverage of positive issues such as accomplishments or human rights issues.[46][47][48] Such negative depictions, including in children's cartoons, are thought to contribute to stigma and negative attitudes in the public and in those with mental health problems themselves, although more sensitive or serious cinematic portrayals have increased in prevalence.[49][50]

General public

The general public have been found to hold a strong stereotype of dangerousness and desire for social distance from individuals described as mentally ill.[51] Japan has been reported to have more negative attitudes than Australia, although stigma appears common in both countries.[52]

Violence

The public fear of violence due to mental illness is a contentious topic. One US national survey indicated that a far higher percentage of Americans rated individuals described as displaying the characteristics of a mental disorder (for example Schizophrenia or Substance Use Disorder) as "likely to do something violent to others" compared to those described as being 'troubled'.[53] Research indicates, on balance, a higher than average number of violent acts by some individuals with certain diagnoses, notably antisocial or psychopathic personality disorders, but conflicting findings about specific symptoms (for example links between psychosis and violence in community settings) - but the mediating factors of such acts are most consistently found to be mainly socio-demographic and socio-economic factors such as being young, male, of lower socio-economic status and, in particular, substance abuse (including alcohol).[54][55][22] Findings consistently indicate that it is many times more likely that people diagnosed with a serious mental illness living in the community will be the victim rather than the perpetrator of violence.[54][56] Violence by or against individuals with mental illness typically occurs in the context of complex social interactions (including in atmosphere of mutually high "expressed emotion"), including within a family setting,[57] as well as being an issue in healthcare settings[58] and the wider community.[59]

Employment

Employment discrimination is reported to play a significant part in the high rate of unemployment among those with a diagnosis of mental illness[60] Schemes to combat stigma have been prioritized by global and national psychiatric organizations, but their methods and outcomes have been criticized as counterproductive.[61]